exercise phys exam 2 Flashcards
PCr (phosphocreatine) is a buffer for ______
ATP
how long does it take to replenish PCr stores?
6 min
creatine loading:
20-25g/day for 5-7 days
what does creatine loading do?
helps increase performance for HIGH INTENSITY exercise
net ATP from glycolysis
2
what is the rate-limiting enzyme of glycolysis
phosphofructokinase
exercise stimulates GLUT4 transporter to:
transform into sarcolemma and let glucose in
insulin does what?
increases glucose in the cell. independent from exercise
blood glucose does what after 1 hr exercise
decreases
what helps prevent decrease of blood glucose during exercise?
ingestion of carbs
how much should you drink every 15-20 min. during exercise to maintain blood glucose?
8-12 oz of a 6% CHO drink
what are the two main pathways in skeletal muscle that increase glycogenolysis?
ephinephrine and Ca++ calmodulin
high intensity, short exercise utilizes what as fuel?
carbs
low intensity, long exercise utilizes what as fuel?
fats
moves lactate into mitochondria for oxidation via MCT (monocarboxylate transporter)
intracellular lactate shuttle
moves lactate to utilizing tissue (heart or slow twitch muscle)
extracellular lactate shuttle
energy in fat
9kcal/g
energy in carbs
4kcal/g
an increase in cyclic AMP causes:
increase PKA which activates hormone sensitive lipase
fatty acids are moved into mitochondrial matrix for beta oxidation by what enzyme?
carnitine transferase
what has to be present to use fat as energy?
carbs
In the Krebs cycle, what are the intermediates for beta oxidation of fats?
carbs
Highly trained individuals utilize ____ as fuel source more than others.
fat
crossover point:
when you start utilizing fats over carbs